Copolymer and detergent composition employing it

1. A copolymer obtained by polymerizing monomers, comprising:

a cationic vinyl monomer (A1);

a cationic vinyl monomer (A2); and

a vinyl monomer (B) of the formula (1) or (2):

CH 2 ═C(R 1 )—CO—NR 2 R 3   (1)

wherein

R 1 is a hydrogen atom or a methyl group, and

each of R 2 and R 3 is independently a hydrogen atom or a C 1-3 alkyl group, provided that the sum of carbon numbers of R 2 and R 3 is from 1 to 4,

CH 2 ═C(R 4 )—CO(O)—(CH 2 ) a —(CHOH) b —CH 2 OH  (2)

wherein

R 4 is a hydrogen atom or a methyl group,

a is an integer of from 1 to 4, and

b is 0 or 1;

wherein

cationic vinyl monomers (A 1) and (A2) are of formula (3):

CH 2 ═C(R 5 )—CO—(O) c —(NH) 1-c —(CH 2 ) d —N + R 6 R 7 R 8 .X −   (3)

wherein R 5 is a hydrogen atom or a methyl group,

each of R 6 and R 7 is independently a C 1-24 alkyl group, an aryl group or an aralkyl group,

R 8 is a hydrogen atom, a C 1-24 alkyl group, an aryl group, an aralkyl group or —CH 2 —CH(OH)—CH 2 —N + R 9 R 10 R 11 ·Y − ;

wherein

each of R 9 to R 11 is independently a C 1-24 alkyl group, an aryl group or an aralkyl group,

each of X − and Y − is independently an anion,

c is 0 or 1, and

d is an integer of from 1 to 10, and

wherein

in monomer (A1) of the formula (3) c is 1, and in monomer (A2) of the formula (3) c is 0.

2. The copolymer according to claim 1 , wherein a content of the vinyl monomer (B) is from 20 to 75 mol % based on the entire monomer content of the copolymer.

3. The copolymer according to claim 1 , wherein

a content of the monomer (A 1) is from 1 to 44 mol %,

a content of the monomer (A2) is from 1 to 44 mol %, and

a total content of monomers (A1) and (A2) is from 25 to 45 mol %, based on the entire monomer content of the copolymer.

4. The copolymer according to claim 1 , wherein a weight average molecular weight of from 10,000 to 2,000,000.

5. The copolymer according to claim 1 , which comprises no cross-linking agent.

6. A detergent composition, comprising:

at least one copolymer according to claim 1 ; and

at least one surfactant.

7. The detergent composition according to claim 6 , which comprises:

at least a copolymer (C1) and a copolymer (C2),

wherein

the content of the cationic vinyl monomers (A1) and (A2) in the copolymer (C2) is larger than the content of the cationic vinyl monomers (A1) and (A2) in the copolymer (C1).

8. The detergent composition according to claim 6 , wherein the surfactant comprises at least one anionic surfactant.

9. The detergent composition according to claim 8 ,

wherein a content of the anionic surfactant is from 5 to 40 wt % of the composition, and

a content of the at least one copolymer is from 0.01 to 5 wt % of the composition.

10. The detergent composition according to claim 8 , which further comprises at most 10 wt % in total of at least one surfactant selected from the group consisting of an amphoteric surfactant, a nonionic surfactant and a semi-polar surfactant.

11. The detergent composition according to claim 6 , which further comprises a silicone oil and/or a higher alcohol.

12. A method for cleaning an object, comprising:

washing the object to be cleaned with a detergent comprising:

at least one copolymer according to claim 1 .

13. The method according to claim 12 , wherein a proportion of the vinyl monomer (B) is from 20 to 75 mol % based on the entire copolymer.

14. The method according to claim 12 , wherein

a proportion of the monomer (A1) is from 1 to 44 mol %,

a proportion of the monomer (A2) is from 1 to 44 mol %, and

the total of the proportions of monomer (A1) and monomer (A2) is from 25 to 45 mol %, based on the entire copolymer.

15. The method according to claim 12 , wherein a weight average molecular weight of the obtained copolymer is from 10,000 to 2,000,000.

16. The method according to claim 12 , wherein the copolymer comprises no cross-linking agent as a component.

17. The method according to claim 12 , wherein the copolymer comprises at least the vinyl monomer (B) of the formula (1).